In the area of computer peripherals, it is known, for example, for a signal path to be equipped with a simple light diode so that a developer or a service technician can determine, at least from the lit or unlit state of such an LED, whether there is a signal at all on a corresponding signal path. But it was regarded as disadvantageous, however, that when such a simple LED is used, essentially only the lit or unlit state can be evaluated as information on the existence of a signal.
Such a display does not say in which range of values a signal is found on a signal path, for example. This means that there is no information, for example, for voltages, on the amount of the voltage, or for alternating signals, on the frequency of this signal, for example.
To obtain such information, measuring devices such as multimeters or oscilloscopes are normally used, with which the signals on the signal paths to be observed are measured and displayed. However, this is very time-consuming, in particular for a plurality of signal paths, i.e., for wiring harnesses, for example, such as flat conductor cable connections between electronic apparatuses, since such signal paths must first be manually broken in order to measure the signal. Furthermore, using a multimeter or oscilloscope or a similar apparatus, each individual signal path must then be separately examined, since the mentioned display apparatuses cannot be simultaneously made available for all signal paths of such an electrical connection.